1. Open a drawing with fileUrl without UI

https://app.kudo.graebert.com/editor?fileUrl=https://xenon-instance-setup.s3.amazonaws.com/001General.dwg&auth=demo1&userId=demouser

“Default Files” in customization.zip package contains:

Workspace → Viewer.xml

Support → setvars.lsp
Support → start.lsp

Customized viewer workspace to hide all UI elements (Default Files/Workspace/Viewer.xml):

<?xml version="1.0" encoding="UTF-8"?>
<workspace>
    <name workspace_name="Viewer" />
    <description description="" />
    <status_bar_visible status_bar_visible="0" />
    <groups/>
    <dockable_windows>
        <window object_name="CommandWindow" visible="0" name="Command Prompt" />
        <window object_name="PropertyWindow" visible="0" name="Properties Window" />
        <window object_name="XRefManager" visible="0" name="References" />
        <window object_name="LayerPanel" visible="0" name="Layer Panel" />
    </dockable_windows>
</workspace>

Created a simple LISP function that sets environment variable to turn of ucs icon (Default Files/Support/setvars.lsp):

(defun initEnv()
 (setvar "UCSICON" 0)
)

Adjusted LISP file that is loaded on startup to load that file and execute the function (Default Files/Support/start.lsp):

...
(load "setvars.lsp")
(initEnv)

Samples

1. Open a drawing with fileUrl without UI